You are shooting just over 1 MOA at 50 yards with your 22 and 1 MOA is a reasonable indicator of good accuracy. Depending on the rifle and ammo it could be indicative of GREAT accuracy.

To move out you just continue to use the same fundamentals you use at closer ranges. The equipment you use can become the limiting factor. You don't mention your rifle brand/model or ammo type. Not all rifle and ammo combinations will hold 1 MOA at 300+ yards even if bolted to the bench.